Means for protecting booster sets.



PATBNTED MAY 30, 1905.

F. L. SESSIONS.

MEANS FOR PROTECTING BOOSTER SETS.

APPLICATION FILED 13110.18, 1899.

2 SHEETSSHEBT 1.

In uerdzwv PATENTED MAY 30, 1905.

F. L. SESSIONS. MEANS FOR PROTECTING BOOSTER SETS.

APPLICATION IILED DEOJB, 1899.

2 SHEETS-SHEET 2- km? or,

UNITED STATES BEST AVAILABLE COPY Patented May 30, 1905.

PATENT OFFICE.

FRANK L. SESSIONS, OF OAK PARK, ILLINOIS, ASSIGNOR TO SIEMENS & HALSKE ELECTRIC COMPANY OF AMERICA, OF CHICAGO, ILLINOIS, A

CORPORATION OF ILLINOIS.

MEANS FOR PROTECTING BOOSTER SETS.

SPECIFICATION forming part of Letters Patent No. 791,220, dated May 30, 1905.

Application filed December 18,1899. Serial No. 740,692. V

To all whom it may concern.-

Be it known that I, FRANK L. SESSIONS, a citizen of the United States, residing at No. 306 Forest avenue, Oak Park, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Means for Protecting Booster Sets, of which the following is a specification.

This invention relates to improvements in means for protecting booster sets of that class comprising a generator connected in series in a circuit and a generator-actuating motor connected in shunt across the line, the purpose of the apparatus being to raise the electromotive force in the line to compensate for the transmission losses in cases where the amount of copper in the line is 'too small for the loads transmitted or where from any other cause such losses are large enough to be serious. In an apparatus of this character it is Well understood that if the current through the motor should be interrupted the booster-generator would immediately begin to operate as a series motor, tending to rotate in a reverse direction from its rotation as a generator with a constantly accelerating speed up to the point where the friction and other 'losses become equal to the energy supplied,

and long before this speed would be attained the entire apparatus would be likely to fly to pieces under the stress of the resultant centrifugal force.

The object of the present invention is to provide an improved controlling mechanism capable of so controlling the action of the apparatus as to insure its safety at all times and prevent any possible accident of the kind referred to, as will more fully appear from the following detailed description of the construction illustrated in the accompanying drawings, in which Figure 1 is a diagrammatic view of a booster set provided with the improved safety devices referred to. Fig. 2 shows a detailed side elevation of the safety-trip. Fig. 3 is a similar view in rear elevation. Fig. 4: is a View similar to Fig. 2, showing the trip as operated.

A designates a suitable generator supply- C is the shunt-wound motor, which drives the booster-generator B by means of any suitable mechanical connection, said motor and generator being usually either mounted upon a common shaft S or mouutedupon separate shafts coupled together to rotate in unison. The motor C is connected in a shunt-circuit 0 across the line a a, and this shunt-circuit is subdivided, as usual, in the two parallel circuits 0' and 0 which are, respectively, the shunt field and the armature circuits of the motor. A circuitbreaker D, inserted in the main line, is provided to cut out the booster-generator B in case of an abnormal rush of current in said line, and a second circuit-breaker E is provided in the circuit to the motor to cut out the latter in case the current through this circuit should increase to an undesirable extent. A starting-box F is also provided in the armature-circuit c of the motor, its pivoted switch-leverf being normally held closed against the tension of a spring f" by an electromagnet f that is connected in series in the shunt field-circuit c of the motor, so that unless a certain current is maintained through the field the starting-box will open and cut out the motor completely by interrupting both its armature and shunt field circuits. Such circuit-breakers and starting-boxes are familiar to those skilled in the art and need not, therefore, be more particularly described.

As thus far described the arrangement of apparatus involves no departure from the existing practice. As a further improvement in accordance with the present invention, however, an additional trip G is applied to the circuit-breaker D and operated by an electromagnet connected in series in the shunt field-circuit c of the motor. As better shownin Figs 2, 3,.and 4, said tripping device comprises a framework which is screwed or otherwise secured to the frame of the circuitbreaker D, the latter being of any suitable type and herein illustrated as the well-known G. E. instrument of that nature. The tripper-magnet g.- is shown as depending beneath the frame 9, and the latter is provided with a depending arm g carrying at its lower end a pivot 9 which supports the usual vibratory armature g. The rear end of thisarmature is loosely connected. at a point slightly above the pivot g with the lower end of a vibratory arm g, that is pivoted at its upper end g to the frame g. Between its ends this arm 9 is bifurcated to contain a pawl g", havingia substantially horizontal rearwardly-projecti-ng lip g, which. is adapted to project beneath the adjacent shoulder g" on a vertical stem G, soas to normally prevent any downward movement of said stem, said shoulder being herein shown as formed by the end of a transverse bar g, which is rigidly inserted in the stem. A spring G inserted within a suitable housing or dash-pot g", provided on the frame g around the stem G, tendsto force the latter downwardly, except as withstood by said pawl g", and the pressure of the shoulder g against said pawl, acting through the arm g and connection. 9 tends to swing the armature 9 down away from the magnet g-about its pivot g, which action of the armature will ermit said arm 6' to swin forwardzfar enough on its pivot to carry the lip g of the-pawl out' from under the shoulder g, whereupon the spring G will expand and The upper end. of this.

depress the stem G. stem; is. rigidly. connected by a cross-bracket g, .and upwardly-extending rod g with the tripping-armature (Z of the circuit-breaker D, so that when said stem G is forced down in the manner described the circuit-breaker will be tripped to interrupt the current to the booster-generator in exactly the same manner as though the tripping-armature (Z had been drawn down by an excess of current through the coil d of said circuit-breaker. The position of the parts at the moment the circuitbreaker is thus tripped isshown in-Fig. 4. The construction of the tripping mechanism is such that although thespring G is one of considerable strength the leverage which it will I exert upon the armature y will be very slight,

so that said armature will normally be held up into contact with its magnet by the shunt-cu rr-ent through the field-circuit of the motor, which current traverses the coil g of the tripping mechanism, owing to; the connection of the latter. in series in said field-circuih'as hereinbefore described. The interruption of the current through said shunt-field either by reason of the opening of the circuit-breaker E or of the starting-box F will then permit the ar.

mature g to drop, with the effect of tripping BEST AVAILABLE COP.

the circuit-breaker D in the manner stated. Such dropping of the armature of; course relieves it from the pressure of the spring G and leaves it free to be again lifted by the attraction of its magnet when the shunt field-current of the motor is restored, whereupon the pawl g will again project into the path of the shoulder g ready to .hold the stem Gand circuit-breaker armature d in their-elevated position when again lifted. This latter action is accomplished manually in any suitable manner, as by means ofthe usual insulated knob jection of the pawl by-the spring. Azlight. adjusting-spring g isi-also herein shown .as

applied between: the tripper-frame g and' armature .gto enable the movement of the armature to be more accuratelycontrolled.

"The tripping device thus described will: be called into-action .to open; the circuitrbreaker D and cut out the booster-generatomwhenever thecurrent thnoughthe shunt-fieldpfi the motoris interrupted in any man.neras, for example,- .by theopeningofi the-circuit breaker E and starting-box F andi if after both circuit-breakers arethus opened the operatoror attendant should inadvertently close .the -ci r.- cuitbreaker:- D- without zfilSl] closing the motor-circuit breaker and starting-box the: former circuit-breaker would obviously open again assoon asthehand-ofi theiattendant had been lifted from it. As aconsequence, therefore, the boostewgeneratorwills becut out at all times exceptwhen its-actuati-ngmotor is energized, and the running awayot said generator under such circumstances; is obviously impossible.

It will be understood that various changes may be made in the details of' the: construction show-n without involving any departure from the broadspirit of the-invention claimed.

I claim as my invention- 1. As a-means for protecting booster sets of that class comprisinga generator connected in series in a main circuit and a generator-actuating motor connected in shunt across the line; a circuit-breaker interposed between the main line and the booster-generator, and an auxiliary trip applied to said--eircuitsbreaker=and controlled by an electromagnet connected in the shunt field-circuit of. the motor, substantially as described.

2. The combination of a booster-generator in series relation. to a circuit, a motor for achating the same in shunt across the line, ieans responsive to predetermined increase r decrease of current in the motor-circuit, nd a circuit-opening device in the boosterircuit governed thereby.

3. The combination with a booster-generabr connected in series in a main circuit and motor for actuating the generator connected n shunt across the line, of a circuit-breaker nterposed between the main line and the poster-generator, and an underload and over- Jad trip applied to said circuit-breaker and perating to openthe latter whenever the curent in the motor-circuit exceeds or falls beow certain predetermined limits, substanially as described.

4. The combination with a booster-generaor connected in series in a main circuit and motor for actuating the generator connected n shunt across the line, of a circuit-breaker nterposed between the main line and the poster-generator, an underload-trip applied 0 the circuit-breaker and operating to open he latter whenever the current in the motorgircuit falls below a predetermined limit, subtantially as described.

5. The combination with a booster-generaior connected in series in a'main circuit and motor for actuating the generator connected .n shunt across the line, of a circuit-breaker nterposed between the main line and the poster-generator, means for opening the otor-circuit whenever the current therein =xceeds a predetermined limit, and means iontrolled by an electromagnet connected in I he motor-circuit for operating said c1rcu1t rreaker whenever the motor-circuit is open, ubstantially as described.

6. The combination with a booster generaor connected in series in a main circuit and motor for actuating the generator connected n-shunt across the line, of a circuit-breaker nterposed between the main line and the ooster-generator, means for opening the motor-circuit Whenever the current therein alls below a predetermined limit, and means :ontrolled by an electromagnet connected in he motor-circuit for operating said circuit- )reaker whenever the motor-circuit is open, ubstantially as described.

7. The combination with a booster-genera- ;or connected in series in a main circuit and motor for actuating the generator connected n shunt across the line, of a circuit-breaker interposed between ,the main line and the iooster-generator, means for opening the notor-circuit whenever the current therein :xceeds a predetermined limit, means for ipening the motor-circuit whenever the curent therein falls below a predetermined limit, ind means controlled by an electromagnet connected in the motor-circuit for operating said BEST AVAILABLE COP? circuit-breaker whenever the motor-circuit is open, substantially as described.

8. As a means for protecting booster sets of that class comprising a generator connected in series in a main circuit and a generator-actuating motor connected in shunt across the line; a circuit-breaker interposed between the main line and the booster-generator,a second circuitbreaker connected in the circuit to the motor, and an auxiliarytrip applied to the first circuit-breaker and controlled by an electromagnet connected in the shunt field-circuit of the motor, substantially as described.

9. As a means for protecting booster sets of that class comprising a generator connected in series in a main circuit and a generator-actuating motor connected in shunt across theline; a circuit-breaker interposed between the main line and the booster-generator, a second circuit-breaker connected in the circuit to the motor, an auxiliary trip applied to the first circuit-breaker and controlled by an electromagnet connected in the shunt field-circuit of the motor, substantially as described.

10. As a means for protecting booster sets of that class comprising a generator connected in series in a main circuit and a generator-actuating motor connected in shunt across the line; a circuit-breaker interposed between the main line and the booster-generator, a starting-box connected in the circuit to the motor and arranged to be held closed against the ten- .sion of an opening-spring by an electromagnet connected in the shunt field-circuit of the motor, and an auxiliary trip applied to the circuit-breaker and controlled by an electromagnet connected in the shunt field-circu it of the motor, substantially as described.

11. As a means for protecting booster sets of that class comprising a generator connected in series in a main circuit and a generator-actuating motor connected in shunt across the line; a circuit-breaker interposed between the main line and the booster-generator, a second circuit-breaker connected in the circuit to the motor, a starting-box connected in the circuit to the motor and arranged to be held closed against a tension of an opening-spring-by an electromagnet connected in the shunt field-circuit of the motor, and an auxiliary trip applied to the first circuit-breaker and controlled by an electromagnet connected in the shunt field-circuit of the motor, substantially as dc scribed.

In testimony that I claim the foregoing as my invention I aflix my signature, in presence of two subscribing witnesses, this 8th day of December, A. D. 1899.

.FRANK L. SESSIONS.

Witnesses:

HENRY W. CARTER, ALBERT H. GRAVES. 

